This paper is a contribution to the studies of sound symbolism, systematic relationships between sounds and meanings. Two experiments were conducted in which native speakers of English were provided with pairs of pre-evolution and post-evolution Pokemon characters, the latter of which were always larger. The participants were given two name choices whose members are systematically different in some phonological properties. The results show the following sound symbolic patterns to be productive: the participants tend to associate post-evolution characters with (1) names containing voiced obstruents ([b, d, g, z]), (2) names with more segments, (3) names containing [a], (4) names containing [u], and (5) names containing coronal consonants. Overall, the current results suggest that phonological properties of names non-trivially affect the naming patterns of new creatures, implying that the relationships between sounds and meanings are not as arbitrary as modern linguistic theories generally assume.